• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Hazard Switch Signal | 2 | 2 | 2 | -- |
Turn Signal Control | 1 | 1 | 1 | -- |
Turn Signal/Multifunction Switch Ground | -- | 2 | -- | -- |
Turn Signal Lamp Ground | -- | 1 | -- | -- |
1. Hazard Lamps Malfunction 2. Turn Signal/Multifunction Switch Malfunction |
The body control module (BCM) controls the hazard lamps based on inputs from the hazard switch. With the hazard switch closed, a ground path is provided on the hazards switch signal circuit, indicating a hazard lamp request. When this request is seen, the BCM will pulse the turn signal lamp supply voltage circuits, illuminating the turn signal lamps.
Exterior Lighting Systems Description and Operation
Control Module References for scan tool information
• | LF Turn Signal |
• | RF Turn Signal |
• | LR Turn Signal |
• | RR Turn Signal |
⇒ | If the lamps do not turn ON and OFF, refer to Turn Signal Lamps and/or Indicators Malfunction. |
⇒ | If the parameter does not cycle between the specified values, refer to Hazard Switch Malfunction. |
⇒ | If one or more of the lamps flash ON and OFF, refer to Turn Signal Lamps and/or Indicators Malfunction |
⇒ | If none of the lamps flash ON and OFF, refer to Hazard Switch Malfunction. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If not the specified value, test the signal circuit terminal G for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |